We've just arrived back from sunny Oregon where O'Reilly's 2010open source convention was being held, and it's been a busy weekof mingling, arguing and general geekery as we hooked ourselves upto the open source electricity mains.

But the rest of the world didn't stand still, and LXF135 has alreadyhit the newsstands - read on for a sneak peek of what's inside, plusquick roundups of the best news stories and forum threads, and aspecial feature on working smarter on the command line.

And if you're looking to save money in these financially uncertaintimes, check out our latest subscription offers.

For a few years now Firefox has been the darling of the open sourcecommunity, even garnering enough cash to run adverts in newspapersto spread the word. But some might say the project has rested on itslaurels for too long, and upcoming browser alternatives such asGoogle Chrome are starting to nibble away at Firefox's marketshare.As our cover feature shows, it's a tight battle indeed, and in termsof resource usage Chrome is quite a long way ahead. Can Firefox stayrelevant? Read the full feature for the answer!

Meanwhile, Launchpad continues to win converts as it seamlessly blendsversion control with bug tracking and community relations, and theOpen University comes to the end of its first course in Linux - did wepass, and would we recommend it?

Being able to see into the future would be quite handy. Apart from clearing your gambling debts and predicting the scripts for Doctor Who, you'd know when the optimum time to expand your RAID array would be. This delightful little command line tool can't help you with the 11.30 at Kempston, or whether that ginger girl will make it to the Christmas special, but it can tell you when your hard drive is going to be full. OK, it might not change your life, but it could be useful before you embark on a major photo scanning exercise or decide to download every single Linux distro. The concept is simple. Dfeta samples the fullness of your drive at regular intervals, does a few sums and then tells you the specific date on which your disk will tell you there's no more room. It's like one of those ‘predict the date of your own death' websites, but not as scary. Even if you're not an IT person responsible for providing storage, this handy little tool is a nice nagging aid to remind you to empty the trash and recycle more often.

Obviously, for this to work, you need to sample regularly. The more samples you take, the more accurate it becomes, since temporary blips are ironed out of the ongoing averages. How often you decide to run it is up to you, but the stored data file is pretty small, although it does keep backups (which leads to some self-fulfilling prophesising over time). But because it's pretty fast and painless, you don't even know it's happening. The best idea is to install it in your path (/usr/local/bin/ or wherever is appropriate on your system) and execute a Cron job. Once a day is probably enough, but you make up your own mind as to how many bitty data files you want in ~/.dfeta. The only remaining conundrum is how to pronounce it. DeeEffEeeTeeAy? Def-Eatah? Dee-Fetah? Hmmm…

Head over to the LXF website and click on the issue cover picturefor more information on Linux Format 135.

Subscribing to Linux Format not only has the benefit of fantasticsavings. Subscribers will also get exclusive, unlimited access to theLinux Format subscriber-only area, featuring magazine PDFs, completeissues and coverdisc downloads! That's access to over 60 issues of Linuxlearning, free to subscribers to download! See our latest offers at:

Got a 64-bit CPU? Make use of it by running 64-bit Windows applications!But there's much more: new icons based on the Tango set mean that Wine'sbuilt-in apps look more Linux-native than ever, and even support foranimated cursors is on the horizon. Plus, better support for HTTP,sub-pixel font rendering for smoother text on LCDs and even bettercompatibility with Direct3D.

Are you bored of ext4 already? Sure you are! Fortunately, OpenSUSE 11.3already ships with support for the Btrfs filesystem, which includes severalinnovations introduced with ReiserFS4 and is set to replace ext4 inthe coming years. Plus you'll find that touchscreen support has beenextended, netbook compatibility has been improved, and you get thelatest Gnome and KDE versions - 2.30 (with a preview of 3!) and KDE 4.4.4.

Distros are supposed to come configured to be safe. They're supposed to haveupdates that fix any security holes that are discovered later. But, as alesson for security students, Damn Vulnerable Linux takes the oppositetack: the website states up front that it's "everything a good Linuxdistribution isn't," which means packages are configured poorly andthere are dozens of exploits ready to be taken advantage of. Clearly it'snot something you want to be running on your main desktop, but if you wantto poke around and find some real vulnerabilities give it a try!

---------------------------------------------------------- 5. This month on the forum----------------------------------------------------------

If you're looking for an open-platform portable gaming device,perhaps you should join in the discussion about Pandora: anARM-powered, OpenGL-enhanced, touchscreen-capable little boxthat - gasp! - even manages to do Amiga emulation. So, if youwant to relive the glory days (or perhaps try your hand at alittle Pandora programming?) then check out the topicand get involved! [1]

No matter how advanced Linux gets, apparently networking is goingto be an issue that crops up time and time again, as OnlyTheTonyfound out on our forums recently - his network card was goinginto a strange sleep mode that caused all sorts of problems,and, after numerous suggestions from other forum regulars,he eventually tracked the problem down and got it fixed. So,if you have a similar problem, check out his fix! Or you couldalways wait for LXF136, which, ahem, might well solve your problemsonce and for all... </spoiler> [2]

We love the command line, us. And the nice thing about mastering itis that your skills are instantly transferrable to any other OS whereBash is available, not least Mac OS X and BSD. Believe it or not, eventhe most advanced users discover new tricks all the time that help pushtheir skills even further, so below we humbly present some tips thatyou might find useful - even if you're a 10-year Linux veteran!

Using !! is a Bash shortcut for "previous command", so if you ever typea long command only to get met with "permission denied" because you didn'trun it as root, try this:

sudo !!

That will run the last command again, this time using sudo. Without this,you would have to use "su" then re-type the command from scratch.

This !! syntax also extends to other parts of commands, for example if youjust typed a really cool command and you think you're going to want itagain in the future, why not save it to a script? Us this to do just that:

echo "!!" > somecommand.sh

Now you can run somecommand.sh whenever you need to.

Have you ever been faced with the problem of a program accessing a file,thus stopping you from working with it? Sometimes it can be a nightmaretrying to find just what program is keeping you away, but if you needaccess now and all other options have failed you, try this command - itwill automatically kill whichever process is holding access to a file:

fuser -k somefilenamehere

Now that you have your file just where you want it, let's take a backupthe smart way - by automagically appending .bak to a filename, like this:

cp somefile{,.bak}

Now we can blank the old file simply by using this beautifully simpleone-liner:

> somefile

That effectively sends nothing to the file, thus blanking it.

Finally, how about a bit of command completion help? There are twoshortcuts here that not many people know, so if you knew these alreadyyou should find someone to pat you on the back for being so clever.

Recently we had the joy of noodling around with someone else's PHP code,and discovered to our horror that they were sending user input uncheckedinto the database - which means that users could easily write evil codeto break the database if they wanted to. It also meant that text withsingle quotes in, such as "I'm Paul", wouldn't work.

So, here's our special newsletter tip for all your PHP programmers outthere: if you're sending any data to a database, even from a trustedsource, you should always send it through the mysql_real_escape_string()function first to make sure that it's safe for database entry.

---------------------------------------------------------- 7. Coming up next issue----------------------------------------------------------

Linux Format 13, on sale Thursday 19 August...

# Networking: fix your problems once and for all. We work you through the most common problems and show you how to solve them yourself.

# Free completely insane gift! We were bored with giving away stickers and posters, so here's something you've never seen before.

# Akademy 2010 show report: what was decided, and how will it affect the future of KDE? Find out for yourself!

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